The present invention relates to liquid flow control systems. It has particular application to monitoring and controlling the flow of liquid radioactive solutions as might be encountered in nuclear fuels reprocessing or in the flow of liquid radioactive waste material into a calcination facility.
Previous devices for flow measurement and control have included, for example, magnetic flowmeters, rotometers and in-line venturi meters. Most of these devices employ instrumentation, for instance signal amplification components, disposed in close proximity to the liquid flow stream to be monitored. Even the simple, in-line, orifice or venturi installations may become plugged or corroded to necessitate maintenance.
Maintenance of any of these devices at a location with high radiation levels must be done remotely and is therefore to be minimized or completely avoided. Complicated maintenance operations that cannot be carried out by hot-cell slave devices necessitate shutting down the process, removing the defective parts and decontaminating them before maintenance is performed in a more accessible location. These type operations are extremely difficult and expensive to perform.
Therefore, in view of these difficulties with prior art systems, it is an object of the present invention to provide a system for flow control with essentially maintenance-free components in proximity to the process fluid.
It is also an object to provide a system for controlling the flow of radioactive liquids with minimum instrumentation within radioactive locations.